The term forged carbon steel represents a combination of two basic metallurgical components, namely carbon steel and forging. Carbon steel is a broad term applied to a range of steel varieties of various compositions excluding stainless steel. Forging is a metal forming process that utilizes repeated force to compress a piece of heated metal stock into the desired final shape. Forging is generally accepted to produce finished items of a better quality due to the inherent lack of imperfections in the steel structure found with other fabrication methods, making the parts well-suited to high temperature and pressure applications. A few common forged carbon steel parts include machine, valve, and piping system components.
Carbon steel is a fairly generic identifier for a range of steel alloys consisting of carbon as the main alloying component along with varying quantities of other elements such as tungsten, cobalt, and chromium. Generally in defining carbon steel, no minimum or maximum concentrations are quoted for these elements, although it is accepted that stainless steel does not qualify. In other words, concentrations of both the primary carbon and secondary alloying elements may be adjusted to suit the intended end purpose of the steel. For example, increasing the carbon content of the alloy increases its hardness while decreasing its ductility.
Forging is one of the oldest metal forming methods and involves repetitive manual or powered impact to force red hot steel into a certain shape. The metal is heated in a forge and hammered over a shaped jig or between the two halves of a fuller set to achieve its final form. Manual forging is carried out by a blacksmith using smaller, handheld hammers, tongs, and chisels, with the hammering typically taking place on an anvil. Forged carbon steel produced by powered forges are hammered by large trip hammers capable, in some cases, of exerting significant amounts of pressure when striking the hot metal.
Forged carbon steel parts are usually believed to be superior to those made by other methods such as casting. This is due to the fact that the hammering of the metal during forming eliminates most of the microscopic crystalline flaws, such as air bubbles and fissures, which characterize cast parts. This structural integrity makes forged carbon steel parts stronger and better-suited to applications that involve high pressures and temperatures. This strength makes these forgings ideal for oil and gas piping systems, machinery parts, and the internal mechanisms of high-pressure valves.